Problems with Kubernetes calling services outside of cluster

General Discussions
1

I have some weird problems on Azure Kubernetes calling outside services, that may either be caused
by Kubernetes, Microsoft or my ignorance.

I am trying to call some other services on AWS and I need to whitelist the IP address of my kubernetes pod calling it. I used the external IP address of the service/deployment named “tomcat” and it worked just fine.

  1. But then I added a second service also with a public external IP address named “pydro”. Suddenly my tomcat pods could not access the AWS services from tomcat anymore, unless I whitelisted pydros external IP address.

  2. Now I created an additional development cluster. It only has the tomcat service. Whitelisting the external IP address did not work for some reason. Then I looked around in the configuration generated by Azure and found 2 “Frontend IP configurations” associated with the Load Balancer “kubernetes” in Azure. After white listing the 2nd IP address on AWS everything worked again. I could not see the other IP address with “kubectl get services”

Is there something wrong with kubernetes, Azure or with me?
I am not really an IT guy so, I don’t take offense if you tell me what I should change…

Thanks,
Klaus

I thought I add the yaml file for what its is worth - in case it helps:

apiVersion: v1
kind: Service
metadata:
name: tomcat
spec:
type: LoadBalancer
ports:

  • port: 443
    targetPort: 8443
    selector:
    app: tomcat

apiVersion: apps/v1
kind: Deployment
metadata:
name: tomcat
labels:
app: tomcat
spec:
replicas: 2
selector:
matchLabels:
app: tomcat
template:
metadata:
labels:
app: tomcat
deployment: test
spec:
containers:
- name: tomcat
image: fourtwentysevenregistry.azurecr.io/application:v1.93
ports:
- containerPort: 8443
env:
- name: JNDI427
value: “demo427”
- name: ENV427
value: “prod”
imagePullSecrets:
- name: yadayadayada

Cluster information:

Kubernetes version: 1.13.12
Cloud being used: Azure
Installation method: Kubernetes wizard

You can format your yaml by highlighting it and pressing Ctrl-Shift-C, it will make your output easier to read.

2

I don’t see any problem with Kubernetes here, it is just about firewall on Azure, as far I can see.

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